Frozen water lines are a common occurrence in the Northern states during winter, especially when there is an unusually long or unexpected cold snap. In addition to damage to the water line and fittings, such freeze damage usually results in a water leak that causes further damage to walls, ceilings and the like. Such leakage and damage may not be noticed immediately and can occur in an area of a building which is not readily accessible. A frozen water line can thus cause extensive damage which is difficult, time-consuming and expensive to repair.
In the past, the most common approaches to this problem have been to wrap the water line with electric heat tape and/or to open a water valve allowing enough flow to avoid a freeze up. There are, however, distinct limitations and disadvantages with these approaches. Both require at least some manual attention and are best suited for periodic, relatively short periods of usage. These approaches are not suitable for freeze line protection over extended periods, such as when the building is unoccupied, and both are relatively inefficient and often result in unnecessary waste of utilities. Also, there is the possibility of overheating and thus fire with electric heat tape.
In addition to the direct and indirect freeze damage, further damage can be done in thawing a frozen water line. Thawing is usually accomplished by directing electrical current through the line which in turn can promote galvanic corrosion in underground lines and fittings, and even cause damage to grounded appliances in the building from stray amperage.
A need has thus developed for an automatic water line freeze control which continuously monitors the temperature in a water line and opens a valve to control flow according to the temperature, without manual attention or undue waste of water.